Controlling mechanism for compressors



Dec. 18, 1928. 1,695,368

R.CONRADER CONTROLLING MECHANISM FOR COMPRESSORS Original Filed Dec. 3, 192,3 i5 Sheets-Sheet l R. CONRADER CONTROLLING MECHANISM FOR COMPRESSORS Original Filed Dec. 3, 19234 5 Sheets-Sheet 2 /y/ y ffzlwf R. CONRADER CONTROLLING MECHANISM FR COMPRESSORS Dec. 18, 1928.

Original Filed Dec. 5, 1923 5 Sheets-Sheet 3 AParental Dec. 1s, i928.

UNITED STATES PATENT oFEicE.I

RUDOLPH coNaAnEa, or Earn, PENNSYLVANIA.

coNTnoLLING MEcHANIsnroa connaissons.

Application vfiled December 3, 1923, Serial No. 678,369'.y Renewed May l11, 1928.

The invention is designed to control compressors, particularly electricalmotor driven compressors maintaining a uniform pressure 1n a receiver and starting and stopping the motor in accordance with the pressure recompressor 5.

quii-em'ents. With such devices it is desirable to start the motor with the compressor running light and to load up the compressor after the motor is in motion and one of the purposes of the invention is to accomplish this under the varying conditions that may arise in the operation. Features of various parts ot the mechanism which form the` subject matter of the invention will appear from the specification and claims. l' The inyention is illustrated in theaccompanying drawings as follows Fig..1 shows a central vertical. section'of'a discharge unloader forming part of the apparatus. i

Fig. 2 a similar view, the View being at ri ht anglesto that of Fig. 1.

ig. 3 a central vertical section of a regulating device.

Fig. 4 a section on the line 4--4 in Fig. 3. Fig. 5 a central section of a part of the switch mechanism and part of the controlling mechanism, particularly tlieretarding device. Fig. 6 a section on the line 6-6 in Fig. 5. Fig. 7 a section on the line 7--7 in Fig. 5. Fig. 8 a side elevation of the safet device shown in section in Fig. 5, the View eing at. ri ht angles to that of Fig. 5.

mechanism.

ling water circulation to the pump jacket.

1 marks the electric motor, 2 the drive pulley of the motor, 3 a belt extending from the drive pulle to the driving ulley 4 of the hese parts may e of ordinary construction. The compressor dischar es through a ipe 6 to areceiver 7. An unloa er isarrange ing abody 8 with a diaphragm-9. A valve seat 10 is arranged in the diaphragm and a vcheck valve 11 operates on this seat. The

check valve is held to its seat by a spring 12. It lias a plunger 13 which operates in a cylinder 14, the effect of which is to allow the check valve to gradually open and stay open during the ordinary pulsations 'of the com- -pressor,

ting the closing stops. The cylinder has a .cap 111a removed gives access to the seat 10.- An unig. 9 a side elevation of the assembled in the pipe 6, the unloader havthe leakage past the plunger permit-` o the valve when the pump which when loader valve seat 15 is arranged in axial aliney ment with the seat 10 and is suiciently smaller than the seat 10 to .be-assembled through the cylinder and the opening for the Y seat -10. An unloader valve 16 o erates on ,the

seat. It has a stem 17 exten ing through a vspider 18. A spring 19 is arranged around tliestem and operates against a shoulder .20

at the end of the stem. A, piston 21 operates against the stem, this piston operating in a cylinder 22. The cylinder isscrewed into a screw-threaded socket 23 extending from the body 8. A gasket 24 is arranged in the bottoni 'of the socket making atight joint as the' cylinder is screwed to place. The' gasket exjoint for the piston even thoughA there may be leakage around the walls of the piston. .By

making the lstem separate from the piston the unloader valve may be put in place and the r spring adjusted prior to the assembling of the cylinder. A ipe 25 extends from the cylinder to a regu ating mechanism in communication with the receiver.

- .T he regulator is formed with a body 26 having an inlet fitting 27 communicating by a pipe 27 lwith the receiver. The inlet fitting leads to a cylinder l28havingtwo sets of radial ports 29 and 29a discharging to a discharge cavity 29". A pistonBO yoperatesin the cylinder over the ports 29--29. When the'receive'r pressure rises to the. maximum the piston is moved uncovering the ports 29 and connecting the receiver with the unloader so as to unload the compressor. -The same movementlcloses the exhaust ports 29.

As the piston returns the ports 29 are closed and the exhaust port 29 opened permittin the air from the unloader to escape throng the front end of the cylinder. i A push pin 31 extends from the piston to a swinging arm 32.

This arm is pivoted at 33 on the body and has projections 34 in which a screw 35 is mounted. A cross head 36 is mounted on the screw and -is adjustable by the screw.,`y

Springs 37 extend-from the cross head to projections 38 on thebody. The angleof the spring to a radial line running from the cross head to theaxis of the arm is so arranged 'with'relation to the length of the spring as to give `a decreasing leverage to the spring with the shortening of the arm equal to the increase in strength of the spring so that with a starting movement of the piston the ce the ports 29a andv thespring 56 operating on 'adjustment of the cross head.' In order to prevent frequent reversalsof the pressure device the arm 32 isprovided with cam surfaces 39vand 39a which are operated'upon by cam surfaces 40 and 40a of a lever 41. The

lever 41 isp ivot'ed at 42 on the body. A Stud 43 extends through an opening 44'in the lever and a spring 45 is arranged on the stud u and adjustedby a nut 46. The force of this lever opposes the initial movement of the arm 32 in both directions but ceases resistance before'the pistonreaches the ports so that there isf an immediate reversal `with the un-v V covering of 'either port.v This specic regulating device forms the'subject matter of a companion application of even date herewith. f The air is discharged from the regulating Y device through an outlet fitting 47 connected by a pipe 48 with a retarding storage chamber 49, ythe retarding storage chamber being connected bythe pipe 25 with the unloader.

The operation of this will be more fully described later. The switch mechanism is controlled by the regulator. A`pipe49 extends l from the discharge chamber 29a-29b of the regulator to a cylinder 50.. The cylinder 50 '3.0 is mounted on va base 51, the base formi-ng a mounting for the storage chamber 49. The Vbase has a socket 52 in which is arranged a gasket 53. The cylinder is drawn into the socket against the gasket by'screws 54. A

piston 55 is mounted in the cylinder-and at the extreme of its movement seats-on the gasket thus preventing a leakage between the walls of the piston and the cylinderf The piston is normally forced upwardly by' a spring'56. A stem57 extends through-the top of the cylinder to a switch block 58 of insulating material.- Two plates 59 are mounted on' the switch block 58 and these are in position to be contacted by contact posts 60, there being two, of the posts 60 connected with the line wire 61 and two of the posts 60 connected with the wire 62 extending from the. switch tothe motor so that with the closing of the two plates 59 ontheposts 60 the two sides of4 the motor are connected'with the two sides of the line'gwire.. :When the pressure in thev receiver rises to a point to move the piston so las to turn the'air or fluid pressure into thedischarge passage 29b the pressure on the piston 55 opens the' s witch'58 and retains it open so long as the receiver pressure is such as to retain the piston in position to open they ports 29. When the portsare 'closed' the 'pressure from the cylinder 50 is exhausted through the piston closes the switch. r It willl be understood that-thesame regulating action of'thepiston which exhausts the ,l air `f rom the cylinder 50 and thus closes vthe l5 'switch also exhausts the, air from the unoperates on a seat 64 and controls the connection between the discharge iitting 47' and chamber 29". This is held to its seat normally by a light spring 63 and has a slight opening 64a'through which the air from the unloader and the retarding storage chamber may escape. As soon as there is a suflioient escape of air from the unloader the unloader loads up the compressor. The time as to the loading of the compressor may be controlled by the size of the escape opening 641with relation to the air trapped in the retarding storage chamber and the unloader.

Thus more time'may be given by increasing the'size of the chamber or by decreasing the size of the passage 64a. 'When the compres sor unloads, however, the valve 63 is instantly opened so that the unloader operates at the same time that the motor is stopped.

It is desirable to provide a means whereby the compressor will be unloaded whenever ,there is a stoppage of the motor through a break in the line, or for other causes than the direct' control. `of the regulator and this is accomplished in the vpref-.went device by the following mechanism :-A valve body 65 is connected by a pipe 66 withthe retarding chamber 49. A valve opening 67 controls the passage ofthe pipe 66 and a needle valve 68 controls the opening. The needle valve has a stem 69 extending to ayoke 70. A Spring 71 voperates against the yoke and tends to open the needle valve. The lowerl end'of the' 'yoke 'is connected with the core 71'l of a solenoid 72 andthe solenoid is connected lby a shuntline 7 3 with the line 62. A pipe 74 connects the'valve body with the pipe 27a and thus with the receiver. When, therefore, there is a break in theline and consequently there is a cessation of current Ain the solenoid the spring 71 opens the valve 67 and permits receiver pressure to pass intoA the retarding' chamber and thence to the unloading valve and thus the compressor is maintained in an unloaded condition so that Iif the line is closed the compressor will be in positionto s'tartagain. As soon as thecurrent is turned on the solenoid will close the valve 67 and permit the compressorto operate under the control of the regulator.

It is desirableto provide the pump with a mechanism :4 water jacket 75is arranged on -the pump cylinder. This is' connected with a source of water supply through a pi e 76.;y Afvalve77 controls the flow of water Fo the jacket. lA valve head 7 8 is arranged in the I val-ve and carried by astem 7 9.: The stemf is secured to a diaphragm 80. The dia'- hragm is clamped on the body by a cap 481 orming a diaphragm chamber 82. .A pipe 49b`extends from thepi e 49^to thediaphragm chamber 82. TW en, therefore, thev receiver mum an air is turned into the discharge passage 29" .it communicates bywayl of the ipe 49 and pipe 491 to the diaphragm cham- Eer closing the valve at the same time that the mechanism liereinbefore described stops j the motor and unloads the compressor. As

soon as the piston 30 uncovers the port 29*.

.on the reduction of pressure the air is exhausted through these ports and relieves the pressure on the diaphragm thus permitting the valve 78 to open so that while the pump is in mot-ion the water circulation may continue.

What I claim as new is 1. In a controlling mechanism for compressors, the combination of a compressor; an electric motor driving the compressor; an

. unloader for the. compressor; an lelectric line supplying current to the inotor; a regulator sensitive to pumpedl fluid controlling 'the unloader; and means lacting" independtl of the regulator for actuating the unloader with a stoppage of the current in the line connected with the electric motor. 2.*In 4a controlling mechanism -for compr`essors, the combination of a compressor;

" vice controlling the unloader inde endently n 4U of the regulator actuated to unloa the coman electric motor driving the compressor; a line supplying current to the motor; a switch controlling the line; a fluid actuated device controlling the switch; an unloader for the`\ compressor; a regulator controlling the unloader and iiuid actuated device; and a depressor with thel stoppage of current in the lne. p' r .4 3. In a controlling mechanism for compressors, the combinationof a'compressor;

. vcontrolling the line; a iiuid actuated 4fdevice controlling the switch; an unloader for the an electric .motorvdriving the compressor; a line supplying current to the motor; a switch compressor; a regulator controlling the unloader and the uid actuated device, said l regulator being sensitive to pumped iuid; l means for retarding the movement of the t unloader "to loaded position after the .movement of the regulator to close vthe switch; and means acting independentlyof the regulater for unloading the-compressor with the stoppage of current in the line.-4

l mi

L4. In acontrolliiig mechanism for compressors, the 'combination 'of a compressor;

anfelectric motor'driving the compressor;

v an unloader forthe compressor; "an electric line supplying current to the motor; a regu.- lator sensitive to pumped iiuid controlling the unloader; means acting independently of the` regulator for actuating the unloader' (pressure reaches the desired maxi-J ne'cted with tconnection leading to a source of pressure; -a valve controlling' said connection; and an electrically actuated device in the line controlling the valve. -v ,l l 5. Ina controlling mechanism for 'com- Lacasse." l 'withthe' stopplage of currentin' tht line cone electric motor comprising a,

pressors,` v the combination of an unloaderl comprising an unloader valve; a stem extend-- 1n fromthe valve; a spring .tensioning the -va ver, secured on the stem; a cylinder arranged over the valve stem; and a piston-in the `cylinder adapted to be assembled independently of the stem for acting o n the valve'.

6. In a controlling mechanism `for comcomprising an unloader valve; 'a stem extendsocket therein; a cylinder seated in the socket; and a piston operating in the cylinder against so pressors, the combination of an 'unloader ing from the valve;|a valvey body having a the valve ste-m adapted to seatv in; the socket. v

7. In a 'controlling mechanism for compressors,`the combination of a controllinvice for the-compressor comprising a ody having a socket; a gasket in the socket; a cylinder seated on the gasket; a piston operating inthe cylinder and' seating at its extreme movement on the gasket; a connection leading .to the cylinder from a source of pumped' Huid supply; and 'controlling'le- .vices actuatedby the piston.

8. In a 'controlling mechanism for compressors, the combination of a' regulator sensitive to pump pressure; an unloader controlled by the regulator; an electric motor driving the compressor; a switch controlling the electric motor; a pressure actuated device controlledby the regulator controlling the switch; and a retar ing device interposedbetween the regulator and the unloader retarding the movement of the unloader to load po- .v

sition comprising a retarding storagechamberv in the connection between the unloader t and regulator, and a restricted leak from the f i chamber, said restricted leak 'dischariigg Y through: the regulator and being close the regulator with-the unloader 1n unloaded position. .c l

unload the compressor actin in' sequence c through a 'neumatic device to c ose the switch and load t e compressor," said pneumatic devicel comprising a retardingvmeans for the unloader having a leak, 'said-leak dischar c I ing to the'regulatorl and bein closed wit the unloader and unloa d Bplsition. l.10. In a pressure con o.' gdevice,

the

12ov l' an electric motor driving the compressor;

combination of a regulator sensitive to pressure and controlling a supply and exhaust of iiuid under pressure; an unloader; and a connection between the regulator and unloadv er comprising a retarding device having a an unloader for the compressor; an electric line supplying current to the motor; a regulator-sensitive to pumped fluid controlling the unlo'ader; means acting independently of theregulator for actuating the unloader with an opening of the line connected with the electric motor comprising a connection leading to a source of pressure; a valve controlling said connection; an electrically actuated device in the line controlling t-he valve; and a retarding device retarding the moving of the unloader to loaded position, said retarding device actinor on the unloader wher` brought to unloadeda position by ,either the regulator or means.

In testimony whereof I have hereunto set my hand. l

RUDOLPH CON BADER. 

